This invention relates to a browning utensil for microwave ovens which includes a body member formed of ceramics, glass or glass-ceramics and a metallic coating.
Food is cooked in microwave ovens by the microwaves penetrating into the food from all sides and causing the molecules to oscillate (thermal oscillations). For this reason, only materials that are transparent to microwaves and do not reflect or absorb microwaves are used as cooking utensils. Therefore, as a general matter, only glass, ceramics, glass-ceramics, plastics and paper can be used. Customary metal pots reflect the microwave energy, thus preventing the cooking of the food contained in them.
The surface of the food remains unchanged during cooking in a microwave oven. Therefore, in order to produce a browning crust, so-called browning dishes are used. These dishes, consisting of glass, ceramics or glass-ceramics, are provided, preferably on the bottom, with a special metal alloy which absorbs the microwaves, causing it to become hot in the microwave oven. As a result of this additional heating, the food becomes crispy and brown.
The metal layers previously used for browning dishes have the disadvantage that they reflect a considerable part of the microwave energy and thus do not convert it into thermal energy.
In addition, the adhesion of these metal layers to the dish is poor since the coefficients of thermal expansion of the metals or alloys used and of the bases of glass, ceramics or glass-ceramics are very different.
There is also the danger that the metal layer can be damaged or that metals dissolve into the food if the coating is applied to the interior of the dish.